Rowan has taken to calling me and Rachel by our first names. It happened suddenly — and pretty much wholesale — about a month ago. “Good morning, Susan,” he said to me one morning as I stumbled into the kitchen. “Did you have a nice sleep?”

“Why yes, Rowan,” I said, slowly. “I did. Did you?”

“Yes, Susan,” he said. “I did.”

Some things are not worth processing before caffeine.

The processing post-caffeine hasn’t been particularly intense, either, at least for me. “Why do you call me ‘Susan’?” I asked him, a few days into the new regime.

“Because that’s your name,” he said, predictably.

I left it at that. For some reason, it doesn’t overly bother me, this shift in nomenclature. After the initial, jarring, effect wore off, I don’t really notice any more, unless someone points it out to me. Maybe it doesn’t bug me because, well, “Susan” is my name.

I should also point out that, for the past two years or so, Rowan has called me “Uh-mum,” which is short for “Other Mom.” The “other” being in relation to Rachel, who scored the coveted title of “This Mom” in the great toddler name shakedown of 2006. I have mostly come to terms with being (at least on paper) the second-string mother, have even come to embrace my title and its short form. But perhaps it is fair to say that being “Susan” is no better or worse than being Rowan’s other mom.

This Mom, however, begs to differ. Rachel has had a harder time with the new, first-name basis. “My name is ‘Mommy,’” she tells Rowan. “Or ‘This Mom.’ Or ‘Mom.’”

“Okay, Rachel,” Rowan will say.

“You and Isaac are the only people in the world who get to call me ‘Mommy,’” she continues. “That’s your special name for me. That’s what I like you to call me.”

“Rachel, do you want to play trucks?”

I can see why it’s frustrating. But here’s the thing: whatever they call us, it doesn’t erase the fact that at 6 a.m., when we hear a small body slide out of bed, pad across his bedroom floor and the hallway, and open our door, we know that it can be nobody else but Rowan (and, eventually, Isaac). Nobody else but Rowan and Isaac will ever stand, small and pajama’d, at the foot of the bed and say, “Rachel, will you please come cuddle me in my bed?”